<template>
	<view>
		<!-- 使用搜索组件 -->
		<my-search @click="gotoSearch"></my-search>
		<view class="scroll-view-container">
			<!-- 左侧的滑动区域 -->
			<scroll-view class="left-scroll-view" scroll-y :style="{height : wh + 'px' }">
				<block v-for="(item,index) in cateList" :key="index">
					<view :class="['left-scroll-view-item',index===active?'active':'']" @click="activeChanged(index)">{{item.cat_name}}</view>
				</block>

			</scroll-view>
			<!-- 右侧的滑动区域 -->
			<scroll-view class="right-scroll-view" :scroll-top="scrollTop" scroll-y :style="{height : wh + 'px' }">
				<view class="cate-lv2" v-for="(item2,index2) in cateLevel2" :key="index2">
					<view class="cate-lv2-title">{{item2.cat_name}}</view>
					<!-- 三级数据列表 -->
					<view class="cate-lv3-list">
						<view class="cate-lv3-item" v-for="(item3,index3) in item2.children" :key="index3" @click="gotoGoodsList(item3)">
							<!-- 图片 -->
							<img :src="item3.cat_icon"/>
							<!-- 文本 -->
							<text>{{item3.cat_name}}</text>
						</view>
					</view>
				</view>
			</scroll-view>
		</view>
	</view>
</template>

<script>
	export default {
		data() {
			return {
				// 窗口的可用高度 = 屏幕高度 - navigationBar高度 - tabBar 高度
				wh:0,
				cateList:[],//分类页数据
				active:0,//当前选中项的索引,默认让第一行选中
				cateLevel2:[],//二级结构数据
				scrollTop:0,//滚动条距顶部的距离
			};
		},
		onLoad() {
			//根据微信自带的api获取当前的系统信息
			const sysInfo = uni.getSystemInfoSync()
			//为wh窗口赋值
			this.wh=sysInfo.windowHeight - 50
			//调用获取分类数据的方法
			this.getCateList()
		},
		methods:{
			async getCateList(){
				const {data:res} = await uni.$http.get('/api/public/v1/categories')
				if(res.meta.status !== 200){
					return uni.$showMsg()
				}
				this.cateList=res.message
				//为二级结构赋值
				this.cateLevel2=res.message[0].children
			},
			//处理激活页
			activeChanged(index){
				this.active=index
				//为二级结构重新赋值
				this.cateLevel2=this.cateList[index].children
				//修改scrollTop的值
				this.scrollTop = this.scrollTop === 0 ? 1 : 0
			},
			//三级商品详情跳转
			gotoGoodsList(item3){
				uni.navigateTo({
					url: '/subpkg/goods_list/goods_list?cid=' + item3.cat_id
				})
			},
			//跳转搜索页
			gotoSearch(){
				uni.navigateTo({
					url:'/subpkg/search/search'
				})
			}
		}
	}
</script>

<style lang="scss">
	.scroll-view-container{
		display: flex;
		.left-scroll-view{
			width: 120px;
			.left-scroll-view-item{
				line-height: 60px;
				background-color: #f7f7f7;
				text-align: center;
				font-size: 12px;
				// 激活项的样式
				&.active{
					background-color: #ffffff;
					position: relative;
					&::before{
						content: '';
						display: block;
						width: 3px;
						height: 30px;
						background-color: #c00000;
						position: absolute;
						left: 0;
						top: 25%;
					}
				}
			}
		}
		.cate-lv2-title{
			font-size: 12px;
			font-weight: bold;
			text-align: center;
			padding: 15px 0;
			
		}
		.cate-lv3-list{
			display: flex;
			flex-wrap: wrap;
			
			.cate-lv3-item{
				width: 33.33%;
				margin-bottom: 10px;
				display: flex;
				flex-direction: column;
				align-items: center;
				image{
					width: 60px;
					height: 60px;
				}
				text{
					font-size: 12px;
				}
			}
		}
		
	}
</style>
